In certain liquid dispensers, printheads are part of a discrete assembly separate from detachable containers, in which a liquid is held in a block of foam or other capillary material inside the container. Known examples of such dispensers and detachable containers are printers and ink containers, respectively. The liquid holding chamber in these foam based containers is vented to the atmosphere through a hole in the top of the container. The container vent hole is sealed during storage and shipment to prevent evaporation from the ink chamber. The container vent is sometimes not functional when the container is installed in a printhead assembly, for example when the user fails to sufficiently remove the vent seal. The printer will not print properly with a malfunctioning container vent.
The same part numbers designate the same or similar parts throughout the figures.